**4. Effect of pesticides on wine quality**

### **4.1 Pesticides effects on the polyphenolic content and antioxidant activity**

A limited number of scientific reports could be found in the literature, regarding the influence of pesticides on the polyphenolic compounds in beverages. In the last years, studies on beer [30–32] and wine [33–35] chemical compositions have been published.

Dugo et al. [33] investigated the phenolic compounds of grapes and wines, after the use of pesticide treatments in the vineyard. Their results indicated that the antioxidant activity of wines was correlated to the content of phenolic compounds. In contrast, each individual phenolic compound was not homogeneous, and the contents were not correlated to various pesticide treatments.

Navarro et al. [30, 31] noticed on beers samples important differences in the total polyphenolic amount after fermentation for samples that contains residues of pesticides. Major reductions were recorded for propiconazole, 70.8%, myclobutanil, 43.0%, fenitrothion, 13.6%, and trifluralin, 6.8%, when compared to the control. Moreover, fenarinol, malathion, methidathion, nuarimol and pendimethalin were not influence by pesticide residues.

In 2011, Navarro et al. [32] observed that not significant differences on the total polyphenolic amount of beer after fermentation with fungicides. In contrast, statistical differences were noticed for the values of color intensity (lower) and tint (higher) in beer.

Recently, Briz-Cid et al. [34] reported that treatment with mepanipyrim decreased 1.2 times the level in monomeric anthocyanin, while polymeric forms increased 1.3 times. Also, after treatment with iprovalicarb the content in the monomeric anthocyanin increased by around 30%. Malvidin derivatives have been affected significantly, increasing up to 42%. Mulero et al. [35] noticed small changes of less than 10%. In his study, quinoxyfen and kresoxim-methyl have provoked the biggest increase in total anthocyanin, while the famoxadone, trifoxystrobin and fenhexamid reduced the anthocyanin content. No significant differences in antioxidant activity were observed. Similarly, Mulero et al. [35] reported that presence of pesticide residues did not influence the antioxidant activity in red wines.

In general, the treatment with fungicides did not change very much the concentrations of monomeric anthocyanins or flavan-3-ol monomers in wine [36]. Exceptions have been reported for treatments with boscalid + kresoxim-methyl which increased the amount of flavonoid groups with 58% and 36%, respectively. Mulero et al. [35] presented similar results for Monastrell wines from grapes treated with kresoximmethyl. The treatment with quinoxyfen indicates an increase of phenolic compounds in wines when compared with control sample. In opposite, when trifloxystrobin was used it was observed a lower total content in phenolic compounds.

Castro-Sobrino et al. [37] indicated that the use of pesticides does not have an effect on anthocyanins. However, tetraconazole use led to a decrease of these compounds.

### **4.2 Pesticides effects on the aromatic profile**

Wines represent a very complex matrix that contains hundreds of volatile aroma compounds. Aroma compounds originate from: i) varietal aroma that come from the vine and is released in the wine during the fermentation process. The most powerful varietal aromas are terpenoids, varietal thiols and methoxypyrazines; ii) fermentative aroma as a result of the synthesis of important volatile compounds through *Saccharomyces* and non-*Saccharomyces* yeast metabolism, are mainly constituted of volatile higher alcohols, acetate and ethyl esters, medium- and long- chain volatile acids, aldehydes, sulfur compounds [38]; iii) aging aroma either in bottles, in oak barrels or with oak chips, staves with the accumulation of characteristic new aroma compounds (**Table 1**).

Wine aroma can vary depending on the geographic area and terroir, viticultural practices, winemaking processes, type of aging and bottling. Moreover, other factors that have impact on the aroma compounds can interact with proteins, oxygen, polyphenols, polysaccharides, and thus modifying the sensorial characteristics of wines. A correct and controlled management of various methods or conditions of winemaking can help improve wine quality thorough removing the unwanted aroma compounds, the residues of pesticides or heavy metals, microbial contamination or oxidation, etc.

*C6-alcohols* belong to the group of C6-compounds and are formed during pre-fermentation stages, especially during harvesting, transport, crushing and pressing of grapes. These compounds are principally related to lipoxygenase activity in grapes or in must which produces aldehydes, then these, in turn, can be reduced to alcohols, by yeasts during fermentation stage. Higher alcohols are formed from their amino acid precursors, then are passed on to the wine, which are liable for fermentative aroma.

Reports suggested that the residual content of cyazofamid, famoxadone, mandipropamid and valifenalate was not affected by the synthesis of alcohols [47]. Similar results were published by other authors, regarding the chlorpyrifos, fenarimol, mancozeb, metalaxyl, penconazole, vinclozolin, fluquinconazole, kresoxim-methyl, quinoxyfen and trifloxystrobin in red wines [48] and with fludioxonil and pyrimethanil in white wines [49]. Interesting, opposite impacts were noticed for other pesticide categories. In red wines, a significant decrease of alcohols was observed when famoxadone, fenhexamid and tebuconazole were used [39, 48]. Contrasting, in white wines an increase of cis-3-hexen-1-ol content was observed in the presence of cyprodinil [49]. The same trend was noticed for tetraconazole in wines, in which the levels of cis-3-hexen-1-ol also increased with 55% [40].

A pesticides treatment that included fluxilazole showed that, in white wines, the content of isoamyl alcohols and 2-phenylethanol was increased with a direct correlation to the dose [50]. Moreover, other studies observed in white wines a decrease of 2-methyl-1- propanol and 3-methyl-1-propanol when fosetyl-A, mancozeb and iprovalicarb were used [41]. Results concerning the decrease of alcohols concentrations in the presence of some pesticides can be attributed to lower assimilation of the amino acid precursor by yeast or modifications in the biosynthesis of amino acids. However, a decrease in the quality of wine was noticed due to considerable increases in isoamyl alcohols contents [48, 49]. González-Álvarez et al. [47]

*Management of Pesticides from Vineyard to Wines: Focus on Wine Safety and Pesticides Removal… DOI: http://dx.doi.org/10.5772/intechopen.98991*



#### **Table 1.**

*Pesticides losses, quality and health risks of wine.*

reported no significant differences in the alcohols level between control sample and wines treated with chlorpyrifos, cyazofamid, famoxadone, fenarimol, mancozeb, mandipropamid, metalaxyl, penconazole, valifenalate and vinclozolin.

*Management of Pesticides from Vineyard to Wines: Focus on Wine Safety and Pesticides Removal… DOI: http://dx.doi.org/10.5772/intechopen.98991*

The level of aldehydes increased slowly in the wine aging stage by effect of the oxidation of alcohols. The principal aldehydes that could be found in wines are benzaldehyde and phenylethanal [51]. Until now, results indicate that pesticides utilization do not influence the aldehyde contents [39]. However, in red wine, fenhexamid seems to be responsible for the increased content of benzaldehyde [48].

Sieiro-Sampedro et al. [40] founded that mepanipyrim influence the release of varietal aroma compounds while tetraconazole have a major impact on the aroma biosynthesis pathways of the ethanol producing yeasts. According to the OAV, the mepanipyrim could offer to wines higher spicy and floral nuances and lower fruity note whereas tetraconazole leads to higher floral and lactic notes. Mepanipyrim (Mepp) and Mep-Form generated a positive increase of the geraniol content, between 27 and 41%, benzyl alcohol between 91 and 177%, benzaldehyde between 51 and 111% and *trans*-isoeugenol between 37 and 308%. This trend was associated with the actions of yeast enzymes glycosidase and hydrolase of which activity is known to increase during fermentation.

*Esters* are produced by yeast during the alcoholic fermentation and play an important role in the fruitiness of wines.

The effect of cyprodinil, fludioxonil and pyrimethanil presented lower levels of hexanoate, ethyl octanoate and ethyl decanoate in white wines [49]. Also, grapes treated with quinoxyfen, kresomin-methyl and trifloxystrobin have decreased the content of ethyl dodecanoate and diethyl succinate in wines [41]. García et al. [49] observed an increased content of isoamyl acetate in the presence of cyprodinil, fludioxonil, chlorpyrifos, feranimol and vinclozolin. The level of ethyl acetate increased also when chlorpyrifos were used, whereas decreased its content with famoxadone and fenhexamid [48]. Other studies did not notice differences in ethyl ester and acetate levels in control sample and grapes treated with cyazofamid, famoxadone, mandipropamid and valifenalate [47]. Similarly, Noguerol-Pato [39] reported no significant variations, caused by treatments with tebuconazole, in the level of isopentyl acetate and most ethyl esters found in Mencía wines. On the other hand, residues of other pesticides seemed to increase the content of isopentyl acetate [41, 48].

*Terpenes* are found in grape skin, have an important role in varietal aroma and contribute considerably to the grape bouquet.

Oliva et al. [48] reported that treatment with some pesticides (famoxadone, fenhexamid, fluquinconazole, kresoxim-methyl, quinoxyfen and trifloxystrobin) presented an increase of terpenoic class in red wine comparative with control sample. Another study by González-Álvarez et al. [47] showed that cyazofamid and famoxadone treatments have a major impact in the synthesis of trans, trans-farnesol of white wines. Also, three fungicides (benalaxyl, iprovalicarb and pyraclostrobin) have altered the geraniol synthesis [41]. On the contrary, Noguerol-Pato et al. [39] observed that tebuconazole caused no important changes in the terpenoic content of red wines.

The treatment with famoxadone and cymoxanil led to a reduction in the content of isovaleric, caproic and caprylic acids, while valifenalate and cyazofamid increased the content of capric acid, according to González-Álvarez et al. [47]. In another study, the quinoxyfen, kresoxim-methyl, famoxadone, trifloxystrobin, fluquinconazole and fenhexamid content decreased the acid concentration in red wines compared with control sample [48].

*Lactones* are obtained through the intermolecular esterification of 4- hydroxyacids. The use of pesticides on crushed Tempranillo and Graciano grapes did not affect the formation of lactones.
